Gas-engine.



i G: A. CLARK.

l GAS ENGINE. APPLICATION FILED APR. 30, 1908.

Patented oct. 6, 190s.

f/z fm-1 l [NVE/vraie. C/aacie l0/*b Arras/yew State of -cylinders, an(

PAT

perron., l

CLAUDE A. CLARK, OF SYRACUSE, NEW YORK.

GAS-Enormi.

Specification of Letters atent.

'Patented Oct. 6, 1908.

Application tiled April 30, 1908. Serial No. @0,092,

To all 'whomit may concern.'

Be'itknown that I, CLAUDE A. CLARK, a

citizen of the United States, residing at Syracuse, in the county of Onondaga and New York, have invented certain new and useful lmprovementainGasEngines, of which the following is 'aspeciiication.

This invention relates to` im rovements in gas engines of the class in whic water is em-l ployed for cooling the cylinders and other parts, and-the invention relates particularly .to a gas engine in which the exhaust pipe is kept cool by the employmentof both Water and air under forced circulation. ,lr-ff The object of the invention is t6 an explosive engine for marine an other uses, of simple, compact and durable construction, and wherein the cylinders are provided with water-jackets in which the Water is supplied and drawn oif by indirect means,

thereby eliminating a number of parts and saving considerable labor and expense for construction, as compared with the engines heretofore made.

A articular object of the invention is to rovlde a main exhaust part'having water- ]ackets for cooling the same, consisting of separate compartments spaced apart and arranged to take the place of water i es and related fittings commonly employed For supplying and carrying away the water. used for cooling the cylinders and other parts of gaso- Iene engines.

'A further object of the invention is to provide an air-cooling co'mpartment to co crate with the waterrjackets for cooling tlib exhaust.

The invention consists principally of one or more cylinders each having a piston and other working parts common to engines of the explosive type.

The invention further consists of a carbureter for sup lying gas or Voil vapor to the `anelcctric spark-coil or other suitable means l gas for driving the engine.v

4The invention further consists of a Waterjacket comprising a hollow chamber disposed around the explosion cylinder, through which water may circulate under pressure from a ump or like means.

`-The invention furtherconsists of an exhaust pipe or art of peculiar torni and con-` struction whic `is mounted on the rear sides of the cylinders. The said exhaust part rovide' inthev detail description Whic 4for igniting' or explodingthel comprising a one-part casting having a large -central cavity or passage connected with the exhaust ports of each of the cylinders, and having its front end closed and its rear end open for the discharge ofthe burned gas and other matter' received from the explosion chamber.

The invention further consists of two sepa-- rate water-jackets or compartments comprising hollow longitudinal chambers one of `which is disposed along the top side of the exhaust-passage, the other disposed oppof sitely along the under side of said passage, Vthe said water compartments being separated from the exhaust-passage byl an integral corrugated Wall or awall provided with radiating ribs, to increase thesurface to be cooledby the circulating water. One of said jackets servingas a receiving pipe to carry the water from the pump to the cylinder jacket; the other jacketserving as A'a conductor to carry the Water away from cylinder-jacket and Waste the same.v

The invention further consists of a third 4compartment disposed in a manner to partially surroun tending from one Watenjacket to the other. This latter com artment preferably extending the full lengtli of the,exhaustpassage and having its opposite ends open for the free admission of air at either end. This air conipertinent is also separated from the exhaustr passage by a corrugated or serrated wall which is provided for cooling the wall of the exhaust-passage, and also for the special purpose of heating the air to be supplied to the carbureter. d the invention further consists of simple means for drawing the tempered air' away from the air-compartment and forcing the same through thc carburetor.

The ile `volition further consists 'of the novel features and combinations of )arts setforth lfollows, and

then particularly pbmtcd out in the claims, reference being had to the accompanying drawing .forming a part of this specification.

Reierring to the drawing, Figure l is a rear side elevation of a tworyiinder engine, showing the location and manner of applying the exhaust parts and carburetor also showing, by partsbroken away, the arrangement of the radiating ribs oi the air-jacket.` Fig. 2 is a vertical crosssection substantially on the vline 2-,2 of Fig. 1, showing the construction the d the exhaust-passage and exv and arrangement of the principal parts oi the air-jacket.

engine; also showing the exhaust-passage and the arrangement of the separate waterjackets and air-j acket also showing the carbureter and related parts, and means for supplying the carbureter with airwarmed in the Fig. 3n is an enlarged detail sectional view, showing a modified construction of the exhaust, the two water-j ackets and the air-jacket.

Similar numbers of reference are assigned to corresponding parts througliout the several views.v

In the drawing, 2 represents a cylinder and an integral portion thereof comprising the upper half of the crank-case.

.represents the lower half of the crankcase formed with a ilange 4.

-5 represents a crank-shaft Awhich passes through the crank-cases, to one end of which is fitted a balance or ily Wheel 6u 7 represents an air-tight hollow compartment comprisin the crank-case:

, 8 represents t e explosion chamber or cylinder in which a hollow piston 9 reciprocally operates, the latter connected to the crankshaft by rod 10. Y

The working arts of my engine may partake of any of tv e well known constructions and may be connected up in any suitable manner. l

11 represents a hollow chamber cast or formed around the explosion cylinder 8, which comprises a` Water-jacket adapted to be filled with cold y'water tol prevent the eigplosion-cylinder from becoming over-heated during the operation of the engine. The water-jacket 11l may be constructed in any suitable manner to properly provide for the cooling of the cylinder.

12 represents a hollow cap mounted upon `the upper end of the cylinder 8, in a man er to provide. a hollow space between the cap an cylinder-head .comprising a part or' the main' water-jacket. A series of suitable bolts are employed tohold the cap in place. v12 rpresents a carbureter, disposed at the rear si es of the cylinders in any convenient .location, but preferably between l'the exhaust parts and the crankcase- The carbureter may be of any suitable form and construction to carry out the working of my en` gine, Vbut preferably consists of a simple part '(capable of supplying gas to 'one or two cyliners.

14 represents the carbureter or manifold, which comprises. a hollow part disposed abovethe'carbureter and connected to the crank-case 7, by vmeans ofa port 15 formed through the casing 2, and through which the gas enters the crank-case 7 beneath the piston, when the latter is moved to its upper position in cylinder 8.

16 represents a pi 'e connecting the carbureterwith the inta e` 14.

Vaporized air or gas is drawn from the I carbureter into the crank chamber 7, by the suction or vacuum produced by each upward stroke of the piston. At the beginning of'each downward stroke of the piston the latter closes the port 15.

17 represents a by-pass formed in casing 2 opposite port 15, itsllower end opening into crank cavity 7, its upper end terminating in a port 18.

' gas at the upper end of chamber 8, andat the S5 instant the' piston reaches its highest point of travel, an electric spark is introduced through an opening 19 and ignites the confined gas, an explosion immediately occurs, which forces'the piston downwardly again, and so on, during the operation of the engine. After each explosion of the gas in cyl'- inder 8 and the resulting downward stroke ol the iston, the gas becomesburnegl and ex'- lpan( ed, and must vbe eXpelledLfrom chamber 8, to make room for a chargeof fresh gas. In order to get nu of the dead gas, an exhaust port 2O is formed through the rear wall of each cylinder at the lower end of chamber '8, opposite the njgas inlet port 18. Port 2O 100 opens into lan e arged cavity of chamber 21 arranged concentric with said port, and the latter is connectedwith an' exhaust passage 22 formed centrall lin a member or part 23. Part 23 is preferably made -of cast iron in one 105 part, and is disposedl horizontally and se cured to the'rear sides of the cylimlers'byy means of bolts 2 4, which pass through lugs cast on the u per and lower sides of sald part, andare tlien threaded into the cylinder walls. The front end of the part 23 is closed,

but the rear end is preferably open and iitted with an exhaust pipe 25.

The exhaust pipes or parts of alll gas engines, being directly connected to the explo 115 sion chambers become highly heated byreason of the constant and rapid discharge of the hot exhaust. In the lpast considerable trouble has been experienced, because of the over-heating of the exhaust parts, which, as a rule, have not been provided with any cooling means. I have found that engines of the class perform their work moreei'fectively through which water 30. `After the hollow space or y 23 outside of the'exhaust passagef22, the said` compartments, 2 6 and 27 being 'separated -rom said exhaust-passage' by fcbrrugated or serrated walls 28. These walls are formed so`- occur onl that the corrugations prcierabl b oth sides of the wall.` The saidr wallsl may however be constructed with 'a plain inner surface and corrugated or serrated on the outer side next to the Water, and produce the same cooling eHect. ,Y A 29 represents e pipe connected to the under side of the rear end of exhaust-jacket 27 received from 'apunp or other source oi supply is forced into sai-d jacket. The water, then circulates through the length of jacket 27 and enters the main cylindenjaclet Il by passing through ports water circulates ar'oun andI cools the mais cylinder it rises to and lls the hollow space beneath 'the cylinder cap 'i2 from/whenceit flows downwardly throught e the narrow duct or passage 3i termed in 4 water space 1'1 an 28. The. space 34 stance, to. serve as a means then passes through a port 32 into upperrexhaust jacliet 26. -The Awater is then carried away and wasted through a pipe 33 which connects to the rear end of the jacket 26. I

' 34 represents a large hollow compartment perierably extendingvthe full length othje exhaust member 23 and comprises the spiace' between the integral cuter` and' inner walls' of the part 23, YeXtr-nniing from the rear edge oi the exhaust-jacket 26 partially around' ge oli excavity separated trom the exhaustpassage 22 by a continuation of the corrugated wall comprises an air-jacket having itsv opposite ends open to admit the atmosphere freelyl This air-jacket is intended inthe Viijrst infor coolingithe. adjacent portion of the exhaustpassage, and

the corrugations of the dividing wall' are' eml ployed for the purpose ot providing a greater oil; it being radiating surface ord'issipating the heat and at thesame time exposing this greater surface to the coolingaction fot the air. 'This air-jacket is provided ici'. another purpose, namely, for heating onteinperingthe air required lfor properly carbureting vgasolene or essential in' an engine of'` this class that t e air be heated to a certain extent before it is drawnl into the carburetor and converted into gas.- -ln this .manner the air-j acket performs two important functions: the cooling of a portion of the exhaust passage by the ireshfair'when irstadmitted to the jacket, and the heatin or tempering `ci the air for carbureting by tie hot corrugated surface ci the wall28. j -.To draw the tempered air from jacketllil providesJ conducting' werdlyand then upwardly throng from either direction.

cylinder',

and in' the center otthe'carbureter-and connects with the intake 'by meanSo a port 37. The tempered nir is drawn from jacket 34 by the intermittent suetionsio'inhalations produced by each' upvrdxstrolre of piston 9, which drawsthegas orva or from the carbureter and intake throught e port 15 as heretofore described.- Under this method of connecting the carbureter'and jacket 34, there is almost a constant inflow of' air through the open ends .of the jacket, While the engine is working,

whi'clpr'events the over-heating of wall 28 of the e aust-passage adjacent to said jacket, and owing to the lfrequency of the strokes of the iston, the air re uired for the operation of 't e carburetor i 'l not bec-ome too hot. The quantity of air required for operating the carbureterand the proper tempering thereof may readily be regulated by the size of the pipe 35 or the port 36. The viporiz-v` ing of the .oil 38 in the carburetor is e by means of a small tube 39 which is disposed in the 4ipe 35 as shown in Fig. 2. This Lsmall'tu e is disposed in a manner to provide a small opening or vent leading from the interior of the pipe 35 into the interior of the carbureter at the point above the level of the oil'. v By arranging the tube 39 in this manner, its outer end being in the jpth of the air ywhich is being sucked from jac et 34, the oil vapor in the carburetor, is siphoned out of the latter and incorporated with the Warm air taken from jacket 34;', thereby producing the gas for operating the engine,

ln Fig. 3 I have shown a modied form of the exhaust part23, which comprises an exhaust-passage 22 havingv a square bore and having itswalls formed lplain or fiat, the upper'and' lou-'er'wate-jac ets 26 and 27 being rectangular in cross-section. The outer surface of the dividing wall 28 between the jackets and the exhaust passage is provided with radiating rib 40 in place of the corrugations shown in Figs. 1 and 2. In shown an air-jacket or compartment 34, which` is preferably formed rectangular in cross-section and detachably Vconnected to the main body of art 23 by bolts 23. The outer surface of" t e dividing wall between the air-chamber and the exhaust-passage is also provided with the radiating ribs 40. The serrated or ribbed surface-4() is provided for the same purpose as described for the corrugations in Figs. 1 and 2. The ribs 40 and also the corrugations, of the water-jacket 27 are intended specifically for heating the cold water as it first comes from the ump so as to prevent too great a chilling eiiect u on the while at the same time t e cold water is intended to reduce the temperature ot the exhaust-passage. The corrugations and'ribs of the u pereXhaust-jacket are intended principalliy for dissipati'ng the heat ected 11o` i Fig. 3 is also received from the exhaust. Thewater received by the upper 'acket of the'exhaust which Q; drawn from the top of the cylinder jacket 11 through the passage 3l will have a comparatively high temperature and will not l have a very great cooling eflect upon the upper portion of the exhaust-passage for that reason, but notwithstanding its higher temerature the fact of its being liquid and i0 orced through the jacket by the action of the pump, will revent the burning outof the upper wall o the exhaust. It is preferred 1n constructing the three jackets of the exhaustpassage, to give to the air-jacket a larger space than to the .water-jackets, so that the air may circulate more freely and rapidly by reason of the rapid inhalations of the air for carbureting. In the modified construction shown in Fig. 3, the means employed for introducing and drawing-off the water from the upper and lower jackets are the same as shown in Figs. 1 and 2, and the means for conducting the air from jacket 84 to the carbureter are also the same exce ting that the pi e 35 is preferablylconnecte to the under si e ofthe air-jacket.

By providing an exhaust part 23 arranged and ap lied as shown, a great saving may be effected) in the casting and linishing of the main cylinders, and renders it practical. to produce an engine of extremely simple and ight design.t By reason of the novel and simple methods of supplying and cariying away the water used for cooling the main 5 cylinder and exhaustpartsfl not only emloy fewer pipes and fittings for the purpose, but am able to supply the jackets of the main cylinders with Water which has been tempered to an extent which cannot injure or distort these parts, and still supply water at a temperature sui'liciently low to effect a proper cooling of the different arts.

Y The provision of the air-j ac iet adds a new element to the cooling of the exhaust, which may be obtained by simply drawing air from the free atmosphere, without requiring any ump or iittings other than the simple airjacket 34. By the employment of the airjacket, as shown, the size of the water-j ackets for the exhaust is reduced, which renders them more effective, for the reason, in the iirst instance, that the water is not liable to become too hot before it reaches the main jacket; and in the second place, the hot-wa# ter from the main jacket is employed tp protect but a small portion of the exhaust-passage on its way to the waste pipe.

It is a natural characteristic of all gas engines, for the gas or vapor to expand, as soon as the explosion takes place in thevcylinder. This expansion does not cease at the end of the receding stroke of the pieten,- but con tinues for a time after the gas or vapor is disicharged into the exhaust part or pipe. The

. resultof this tendency to prolonged or conlarge number of marine engines in use at present, are equippedwith submerged exhausts, which are employed chieily iccause they serve the desired purpose of a muflier or deadener of the annoying soun-ds of the exhaust, and these appliances are usually rovided with anexpansion chamber, which 1s disposed between the engine and the discharge nozzle. The expansion chamber having a lower temperature than the exhaust pipe leading to it, creates a slight condensation of the gas and vapor and thereby lessens the tendency of the exhaust parts to become choked and the discharge to be retarded. It is an object of my invention to accomplish this desirable result without the necessity of providing any extra parts, such as the expansion tank or chamber referred to. As hereinbefore explained, the cold water employed for cooling my engine and exhaust parts, is first admitted'into/the lower jacket 27 of the exhaust, and from this part it Hows into and circulates around and over the ex lesion chamber; Applyin the water at its cwest temperature to the ower compartment 27, brings the water into contact with a comparatively large area of the surface of exhaust-passage 22, where it exerts a cooling eilect upon the walls of said passage sufficient to cause a condensation of the hot gas and vaporwithin the said passage, and the result is that there is no tendency whatever for the exhaust chamber to become choked. The water in turn is also slightly tempered by passing through the lowerv exhaust-jacket so that when it enters the mam jacket of the cylinder it is not too cold. The air drawn into the airjacket 34 will exert a similar influence upon, and materially. 1ncrease the condensation in the exhaust.

Any number of cylinders may be joined to form an engine, and the exhaust-passage may be east in different lengths to suit the size of the engine. The only change required to be made in the said parts, for the different sized engines being 1n the lnumber of the orts for the exhaust and for the assage ofP the water out of one jacket and into the other jacket of the exhaust.

Under the construction and arrangement f of the arts as shown and described herein, am ab e to greatly reduce the number of water pipes and other fittings, and to accomplish the cooling of the various parts of my engine, as well as, to supply warm an'. for the carbureter in a simpler, more eil'ective and less expensive manner than has heretofore been done.

Obviously some changes or modiiications ses? avenants corr indeiihaving awater-jacket and an exhaust port, an exhaust-member mounted on the Vside of the cylinder andconnected thereto by means of said port, separate water-spaces to cool said exhaust-member, one of said water-spaces disposed on top, the other disposed on the underside of said exhaustmember, 'a port to connect said lower waterspace with the lower end of the jacket of said cylinder, a port to connect said upper water-space with the top of said cylinder jacket, an inlet to connect said lower waterspace with a source of cold4 water supply, an over-flow pi e connected to said 'upper water-space or drawing the hot-water away from said. cylinder, an air-jacket disposed concentric t0 said exhaust-member between said upper and said lower water-space, a carbureter o eratively connected to said cylinder, an

i jacket with said carbureter, adapted to 'conduct lioct-air from the air-jacket to said carbureter, substantially as described.

2. An explosive engine, comprising a cylinder surrounded by a water-jacket, an. exhaust port in said cylinder, an exhaustmember having an exhaust-passage connecting with said port, a water-s ace `disposed along the underside of said ex aust-passageA cormecting with the lower end ot the jacket of said cylinder, a water-s ace disposed along the upper side of said ex aust-passage connecting with the upper end of the jacket of said cylinder, an air-jacket'disp'oscd along the outer side of said exhaust-passage beof said air-jacket eing open t0 admit air drawn from the atmosphere, a carbureter disposed-at the rear sideoi said cylinder, an intake mounted on the rear side of said cylinder, and a' ipe forming a passagefcrhotair from sai air-jacket through said" carbureter into said intake,sub'stantially as described.` i.

inder having an exhaust port, an exhaustmembcr having` an exhaust-passage disposed centrally therein Aand connecting with 'the exhaust port of said cylinder, the said exhaust-passage formed by a corrugated. wall inclosed in a concentric casing, a waterjacketdisposed on theupper side of said exhaust-passage, a water-jacket disposed a pipe connecting said air- 3. An explosive engine, comprising a 'cyl-1 haust-passage between said water-jackets,

adapted to coperate with said water-jackets for v cooling said exhaust-passage, substan-l tially as described.

4. In a `gas engine,l the combination with a cylinder having a water-jacket formed around and ab'ove the same, and having an exhaust port, of an exhaust-passage formed by a corrugated wall and connecting lwith the port in said cylinder, the said exhaustpassage surrounded by an integral outer casing disposed parallel to said corrugated wall, a'water-space disposed on the upper side of said passage .between said casing and said corrugated wall, awater-space disposed on the underside of said passage' between said .casing and said corrugated wall, an `inletpipe to connect the lower water-space with asource of cold-water supply, a p ort to connectthe lower water-space with the waterjacket of the cylinder, a port to connect the ulpper water-space with the water-jacket of t 1e cylinder, a pipe to drain the water from the upper water-space,4 an air-jacketdis osed between said casing and said corrugate wall the upper and lower edges thereof abutting lthe outer edges of said upper and said lower water-spaces, the opposite ends of said airjacket bein open for the admission of air t0 cool said ex aust-passage, the air in said airjacket adapted to be heated by contact with said corrugated wall, a carbureter attached to therear side of said cylinder, and a plpe to conduct .the heated air from said air-jacket .to said carbureter, substantially as described. j y

5. I nan exhaust engine, the combination with a plurality of explosion cylinders having separate water-spaces, each cylinder provided with an exhaust port, of an exhaustmember comprising a one-part casting having a central passage formed by a corrugated wall inclosed in an integral outer shell and connecting with the exhaust port of each cylinder, a water-jacket disposed on the upper side of said central passage and connected to the water-space of each cylinder, a waterjacket disposedl underneath said central passage and connected to the water-space of each cylinder, and an air-jacket comprising a hollow compartment having its op osite ends disposed concentric to said centra passage' between said upper and Isaid' lower water-jacket, adapted tocoperate with said water-jackets for cooling `said central passage, substantially as described.

' 6; In an explosive engine, the combination witha cylinder surrounded by a water-coinpartment and provided with an exhaust port, of a member having a central exhaustpassage formed within a corrugated wall and connected with the exhaust port of said cylinder, the said member having a plain outer underneath said exhaust-passage, jand an casing arranged concentric to and spaced 65.7,

,air-jacket, disposed concentric to said ,ex-I from said corrugated wall, a water-jacket Il. `v

formed in the upper side of said member between said casing and said wall, and connected with said Waterscompartment', and having an outlet ort for Wasting water received from said water-compartment, a water-jacketformed inthe under side of said member between said casing and said Wall connected to said water-compartment, and having an inlet-port for receiving cold Water for cooling said exhaust-passage and said cylinder, and an air-jacket formed inv 'sald member between said casing and said wall and between said water-jackets, adapted to cooperate with said water-jacket for cooling said exhaust-passage, substantially as described.

7. In an explosive engine, the combination i i' 'with a cylinder surrounded by a water-compartment and rovided with an exhaust port, 'of a member' iiaving a central exhaust-pas ,sage connected with the exhaust port of said cylinder, the said member having a plain outer casing arranged concentric to said exhaust-passage, a water-jacket formedl in the upper side of said member between said casing and said exhaust-passage and connected vwith the Watencompartment, and having an outlet-port for wasting hot-water received from 'said water-compartment, a waterjacket formed in the under side of said member between said easing and said exhaustpassage and connected to the water-compartment of the cylinder and having an inlet-port for receiving cold-water for cooling said ex haust-passage and said c linder, an airjacket formed in said mem erbetween said vcasing and said exhaust-passage and between said water-jackets, adapted to coperate` with said water-jackets for cooling said exhaust-passage, a carbureter operatively connected with the cylinder, and a pi )e connecting said air-jacket With said car ureteradapted to supply said carburet'er with air tempered by the heat of theexha'ust, substantially as described.

8. A gas engine, comprising a plurality of cylinders, each having a water-jacket and an nindependent exhaust port, an exhaust-member comprising a one-part casting secured in .horizontal position to the rear sides of said cylinders, said exhaust-member having a common central passage open at one end and connecting with each cylinder by means of .said exhaust ports, a water-spacecomprising a longitudinal compartment, one disposed above andthe other disposed beneath said central passage, a pipe connecting to the lower compartment adapted to suppl cold- Water to said compartment, ports for t e pas-- sage of the water from said lower compart; ment into the jackets of said cylinders, ports for the passage of the water from the top of each cylinder into said upper compartment, an air-jacket comprising a chamber having open ends partially surrounding said central passage and extending from one exhaust water-space to the other, an intake mounted on the r'ear sides of said cylinders beneath said exhaust-member, a port to connect each cylinder with said intake, a pipe connecting at one end with air-jacket the other end connecting with saidI intake, and a carbureter mounted on saidpipebetween said air-jaczet and said intake, substantially as described.

9. In combination with the cylinder of an explosive-engine having a water-jacket, an exhaust-pipe having an outer easing and two oppositely disposed water-spaces between the outer casing and said -exhaust pi e, an air-space disposedv between said ex iaustpipe and said casing andbetween said waterspaces, means for circulating water through one water-space of the exhaust-pipe to the water-jacket of the. cylinder, and from the water-jacket of the cylinder to the second .watersspace ofthe exhaust-pipe, a carburetor mounted in operative position on the side of the cyhnder, and a pipe to conduct air from said air-space to the carburetor, substan? tially as described.

10. An explosive engine, comprising a cylinder-provided with water-spaces and an exhaust port, a corrugated exhaust-pipe inclosed in a easing and connected with the exhaust port of the cylinder, a water-jacket disposed on the upperside of said exhaustpipe, a Water-'jacket disposed on the under side of said exhaust-pipe, a pi )e for supplying cold-water to the'lower jacket of said eyhaustipe, a pipe to carry away the water from te upper jacket of said exhaust-pipe, and an air-jacket disposed between said exhaust-pipe and casing and separating said upper and lower 'waterjackets, substantially as described. j

11. An eX lesive-engine, comprising a cyl,- inder provi ed .with water-spaces, an exhaust-pipe .inclosed in an integral outer shell two water-j ackets disposed between said pipe and said shell for cooling said exhaust-pipe, one of said jackets disposed on the upper side, the other jacket disposed on the under side of said exhaust-pipe, an air-chamber disposed concentrie to said exhaust-pipe between said water-jackets, a carbureter to supply gas to the cylinders, an intake interposed etween the earbureter and cylinder, and a pipe connecting said air-chamber with the earbureter and intake, adapted to sup ly the carbureter with air tempered by the ieat of said exhaust-pipe, substantially as described. In testimony whereof I aliix my signature in presence of two witnesses.

CLAUDE A. CLARK 

